Linear polycarbonates from bis (hydroxyethoxy) aromatic compounds



United States Patent :LINEAR BOLYCARBONATES EROM :B SaI i QX E DXY) A A IC ACDMPQUNDS John R. Caldwell, Kingsport, Tenn.,.assignor to Eastman :Kodak iCompany; Rochester, ?N. Y .a corporation of New Jersey No Drawing. Application January 26, 1956, Serial No. 561,663

This invention relates .to highly polymeric linear polycarbonates prepared by thecondensationtof ('1) one mole proportion of a 2,'2-arylenedioxydiethanol having the general structure wherein "X represents an aromatic nucleus which is at- :tached to the oxy atoms at nuclear para positions as furtherrdefined hereinbelow with (2) from about 1.5 to about 3 mole proportions of an alkyl carbonate containing'from 3 to carbon atoms in the presence ofanester interchange catalyst. This invention also relates to the process involved in preparing thesepolycarbonates and "to the fibers, films and molding compositions prepared from these polycarbonates.

Atcopending application filed December 8, 1953, by D. 'D. Reynolds and John Van Den 'Berghe, Serial No.

Patented July 16, 1957 12 Apparently the discovery of the instant invention is predicated upon the peculiar structure of the 2,2'-arylenedioxydiethanols which permits the reaction to proceed in the presence of certain catalysts so as to produce a -397,'040,-disc1oses highly polymeric linear polycarbonates prepared by the self-condensation in the presence of an ester-interchange catalyst of a 4,4-bis(ti-hydroxyethoxy) biphenyl-bis-(alkyl or aryl carbonates) or substituted "derivates thereof. The polycarbonates which can be prepared'according to the process of-theinstant invention include those described in the Reynolds and Van Den 'Berg'he-application. Moreover, linear polycarbonates of aromatic character have also been described by Carothers and his followers including polycarbonates prepared from p-xylylene glycol condensed with an alkyl carbonate. According to Carothers, polycarbonates can be prepared by alcoholysis in the presence of an alkaline catalyst.

The superior character of :the present invention is quite surprising tinview of the fact'that neither hydro- 'quinone norp-xylylene glycol react directly to :form a highly polymericlinear polycarbonate by means of simply heating a mixture of the dihydroxy compoundand an .Eandthen more water, after which the organic solvent =must be removed before the final polymerization which is accomplished by heating theintermediate product. It

is obvious that this series of required operations adds ggreatly to the'cost of the process and presents serious problems to beovercome in order to accomplish commercial production. In contrast to this, the inventor has discovered a process for obtaininga high molecular weight polycarbonate by merely heating a 2,-2-arylene-dioxydiethanol with ,an -alkyl carbonate in the presence of a specific class ;of ester-interchange catalysts.

meric,linearpolycarbonates whiehhave high molecular weight linear polycarbonate. There is nothing in the prior art which serves as a-basis for predicting such a result. It is well-known that preparation of polycarbonates is complicated by many difficulties, hence the discovery of the instant invention is all the mo u xpe t d It is an object of thisinvention meric linear polycarbonates.

It is a further object of this invention to provide a process for preparing such linear polycarbonates by heatto provide highly polying a 2,2-arylenedioxydiethanol with an alkyl carbonate I in thepresenceof an ester interchange catalyst.

,It is a further objectof this invention to provide an unexpectedly efiicacious species of this process wherein the Icatalystpis a magnesium, calcium or strontium bimetallic complex with alurninum or titanium.

It isa further ob'ectof this invention to provide molds co pos tions fibe andrfi m f o such'h po excellentphysical c a a t ist s u a t eperc ntag of e cnga onat inacity, elasticrecovery, work recovery,stressqelaxation,

jtensile strength, resistance of films to tearing :and repeated folding, modulusiof elasticity, electrical properties, light colontetc. v,

Inaccordance with anembodimentof this invention there is provided a process for preparing a highly polymeric linear polycarbonate which,comprises condensing (1) a 2,2'rarylenedioxydiethanol having the following general formula:

{wherein X represents an aromatic nucleus containing from 6 to 20' carbonatoms which is connected to the oxygen atoms of the above general formula by para- 40 i-p it on ddinkase d rec a e 1 t 1 an -ar 1 an a ka in earth meta bimet l lower alk xid slats w th tlk lowe -alky rbo e in the p es nc wherein -;the second rnetalis selected from the group cons n 19 lum um and-titan u The 2,2 arylenedioxydiethanols defined byithe general formula set forth-above include a large variety of different compounds wherein X can -be derivedfroman aromatic nucleusas illustrated by the following structural'formulas:

.TQOTCHmmTQTl-O O omnOmr-o 0 O0 O-NHOCHz-ONl T-O employed in an amount of from about 0.1 to about 2.0%

based on the weight of 1,5-naphthalenediol. This reaction is advantageously carried out in an autoclave in an inert solvent such as an alkanol, 1,4 -dioxane, tetrahydrofuran, methoxyethyl alcohol, etc. The lower alkanols are generally to be preferred. Although ethylene oxide is to be employed in this illustrative process to produce a compound suitable for the preparation of a highly polymeric linear polycarbonate, it is apparent that the related homologs can be similarly prepared employing other alkylene oxides. Such homologs are not to be employed in accordance with this invention but can be used in preparing polyesters, alkyd resins, polyurethanes, etc.

The following example will serve to illustrate the preparation of one of the 2,2-arylenedioxydiethanols employed in the instant invention.

Example 1.-Preparati0n of the LS-di-(fi-hydroxyethyl) ether of naphthalene Ninety-five grams of 1,5-naphthalenediol, 200 cc. methyl alcohol, 57 g. ethylene oxide, and 1.0 g. potassium hydroxide were placed in an autoclave and stirred at 120 for 4 hours. The product was filtered and the crystals dissolved in 1 liter of hot dioxane and poured with stirring into 2 liters of 0.25 percent aqueous sodium hydroxide solution to remove unreacted 1,5-naphthalenediol. The product was filtered, washed with cold water, and dried. The crystals were recrystallized from a mixture of methoxyethyl alcohol and water. A yield of 85 percent of the 1,5-di(fl-hydroxyethyDether of naphthalene was obtained: melting point 181 C.; carbon found 67.8%, galguyl ated 67.7%; hydrogen found 6.34%, calculated Examples of various alkyl carbonates which can be employed in accordance with the process of this invention include diethyl carbonate, dipropyl carbonate, dibutyl carbonate, di-n-hexyl carbonate, ethylene carbonate, propylene carbonate, di-isopropyl carbonate, ditertiarybutyl carbonate, etc. It is especially preferred to employ di-n-butyl carbonate because it boils at temperature high enough to give a satisfactory reaction rate, and at the same time, the butyl alcohol can be distilled readily from the reaction mixture.

Although any of the known ester-interchange type polyesterification catalysts would be supposed to elfectuate the process of this invention, .it has been found that the employment of a specific type of catalyst produces the especially worthwhile highly polymeric linear polycarbomates of this invention. This is surprising since it would ordinarily appear that any of the ester interchange catalysts would be essentially equivalent to any of the others. However, it has been found that the alkaline earth metal 4 bimetallic complexes described in U. S. Patents 2,720,502 and 2,720,506 produce especially advantageous results. These catalysts have the following general formulas:

wherein M is an alkaline earth metal such as magnesium, calcium or strontium and R is an alkyl radical containing from 1 to 6 carbon atoms.

Examples of catalysts which can be employed are magnesium aluminum tetrabutoxide, calcium aluminum tetraethoxide, strontium titanium hexapropoxide, magnesium hydrogen titanium hexaethoxide, etc.

The catalysts are advantageously employed in an amount of from about 0.005% up to about 0.02% and preferably from 0.006% to 0.01% based on the total weight of the reactants being employed. Higher and lower percentages can also be employed.

The first stage of the condensation reaction is carried out by heating the reactants in a vessel equipped with a distillation column whereby the alcohol corresponding to the alkyl carbonate is removed from the reaction mixture by an ester interchange reaction. After this first stage of the reaction is essentially complete, it is advantageous to then increase the temperature to about 200 C. or higher (advantageously from about 200 to about 270 C.) and then stir the reaction mixture under greatly reduced pressure in order to allow the volatile reaction products to escape from the viscous melt. These details are essentially equivalent to the analogous details of carrying out the condensation of glycols and any of the bifunctional carboxylic acid esters in preparing highly polymeric linear polyesters and it is therefore not necessary to indulge in a lengthy description of the process for the preparation of the novel polycarbonates of this invention.

This invention can be further illustrated by the follow- 7 ing examples of preferred embodiments although it will be understood that these examples are included merely for purposes of illustration and are not intended to limit the scope of the invention unless otherwise specifically indicated.

Example 2.P0lycarb0nate from One hundred and ninety-eight grams (1.0 mole) of 2,2'-(p-phenylenedioxy) diethanol and 348 g. (2.0 moles) of di-n-butyl carbonate were placed in a reaction vessel equipped with a stirrer, a distillation column, and an inlet for purified nitrogen. A solution of 0.02 g. magnesium titanium butoxide in 1 cc. of butyl alcohol was added as catalyst and the mixture was stirred at 180-200 C. in an atmosphere of nitrogen. Butyl alcohol was dis tilled from the reaction mixture as the ester interchange took place. The temperature was then raised to 240 C. and held for 1 hour. A vacuum of 0.1 mm. was applied and stirring was continued for 4 hours. A clear, highly viscous melt was obtained.

The product had an inherent viscosity of 0.61 when measured in a solution of phenol-40% tetrachloroethane. It melted at 144147 C. and was soluble in tetrachloroethane, butyrolactone, and sulfolane. It gave strong, elastic fibers when-extruded through a spinneret. The polycarbonate was molded readily by standard methods in an injection molding press and the molded objects obtained showed excellent dimensional stability. The polycarbonate was also useful as an insulating covering for electric wire. Films made from the polycarbonate Were valuable as protective Wrappings.

Example 3.Polycarb0nate from (no-omom-o-O 2S0! 'nol was prepared meltedat 1'50 160 carbonate was valuable'asamolding plastic, wrapping material, and covering for wire. It was also 1 anilide was made as described above.

areas Three hundred and 'six 'grarns (1.0 mole) of 2,2'-'(sulfonyl-bis(p-phenyleneoxy)') -c'liethariol and 348 "g. (2.0 moles) of dibutyl carbonate were .placed in a reaction vessel as described in Example A solutionof 008 .g. magnesium titanium -butoxide in 2 cc. of butyl alcohol was added :as catalyst, andthe mixture was stirred at ISO-220 C. :in-a stream of pure nitrogen. Butyl alcohol was removed through the column. The temperature was then raised to 220 C. and held for 1 hour. A vacuum "of 0.1 'mm. 'was applied and stirring was continued for 5 hours to give ahighly viscous melt.

The product has an inherent viscosity in 60% phenol- 40% tetrachloroethane of 0.5 5. It melted at 145l55 C.

Strong, elastic fibers were obtained by melt spinning the,

polycarbonate. The polycarbonate was particularly useful as a molding plastic and as "a"wir'e"insulator. It also was useful as a photographic base for both black and white and color types "of silver halide photographic 'emulsions.

Using the general procedure outlined in Example 2 the polycarbonate of 2,2"-'(oxobis (p-'phenyleneoxyn 'dietha- C. This polya protective useful asa photographic film base.

Example 5 .-Po lyc'dfb'ofidte from V on.

The polycarbonate from 2,2-(isopropylidene bis(p- -phenyleneoxy) diethanol wasmade -by the'general pro cedure described above. V was employed as the catalyst. The polycarbonate melted Calcium aluminum butoxide at 120l30 C. This polycarbonate is of particular 'value as an ingredient of lacquers and varnishes because of its solubility properties.

Example 6 .P0lycai'b0nate.- from no-omom-oQ-Oo-omomdn Example 7.P0lycarb0nate from The polycarbonate of 2,2'-(ethylenedioxybis (pphenyleneoxy))diethanol was made as described above. It was useful as an ingredient of paints, lacquers, and other protective coatings.

Example 8.P0lycarb0nate from Ho-omom-oO-o o-rrn-oo-omcmon The polycarbonate of p,p-bis(2-hydroxyethoxy) benz- It was valuable for the production of fibers, films, and molded plastics.

Example "S -Polycarbonate from the ;1,5,-1 ii-()-hydroxyethyl)ether of naphthalene l,4- bis(2-hydroxyethoxy) benzene melts at only C.

It would ordinarily be supposed that the polycarbonate from the naphthalene compound of Example 9 would represent no improvement whereas it was indeed most unexpected to find that the greatly improved product melting at 210 was obtained. This is an unusually high melting point for a polymer which contains ether linkages.

Other polycarbonatescan be preparedin accordance with this invention employing any or the other 2,2- arylenedioxydiethanols. Similarly, any of the other alkyl carbonates can be employed in the processes of preparation. Moreover, a'ryl carbonates are also operative but are not generally preferred since the alkyl carbonates are more. advantageouslyemployed. Any of the catalysts covered by-the-above general formulas can also be employed.

According to an embodiment of this invention, there is provided a' novel class of polycarbonates produced in accordance with this invention which contain recurring units or;groups 'havingthe following general formula:

without success, as discussed in the copending application of Reynolds et a1. referredto hereinabove:

wherein R is a lower'alkyl radical and R represents a radicalsuch as "SOzor CO-- or the. like.

When each- R is ethyl and Ris -'SO2, the product employed Ti(OC4H9)4 as the catalyst was a brown, glassy, noncrystalline, brittle materialwhich was not considered satisfactory for-fibers, film, molding compositions, etc. It appeared that some decomposition had occurred.

When each R is. ethyl and R" is --'CO, the product employed either Ti(OC;H9)4 or "LiAl(OCzH5) as the catalyst was a dark, non-crystalline mass which melted only upon heating to about 300 C. with considerable darkening which appeared to be due to some decomposition phenomena.

Although the invention has been described in considerable detail with reference to certain preferred embodiments thereof, it will be understood that variations and modifications can be efiected without departing from the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

1. A highly polymeric linear polycarbonate containing recurring groups having the following general formula:

wherein Y represents an aromatic nucleus which is connected to the oxygen atoms in the above general formula by para linkages directly attached to an aromatic nucleus and which is selected from the group consisting of the following radicals:

O G O NH-C 00 2. A highly polymeric linear polycarbonate containing recurring units havingthe following formula:

3. A highly polymeric linear polycarbonate containing recurring units having the following formula:

4. A highly polymeric linear polycarbonate containing recurring units having the following formula:

5. A highly polymeric linear polycarbonate containing recurring units having the following formula:

0 0 -o-orn-om-oGii-rmQ-o-om-om-o-ii- 6. A highly polymeric linear polycarbonate containing recurring units having the following formula:

0 10 O-GHr-CHz-O-ii- 7. A process for preparing a highly polymeric linear polycarbonate which comprises condensing in the presence of a catalyst selected from the group of those having the following general formulas:

wherein M represents an alkaline earth metal and R represents a lower alkyl radical, (1) a 2,2'-arylene-dioxydiethanol having the following general formula:

wherein X represents an aromatic nucleus containing from 6 to carbon atoms which is connected to the oxygen atoms of the general formula by para linkages which are directly connected to a benzene ring, with (2) a lower alkyl carbonate at an elevated temperature under an inert atmosphere with agitation.

8. A process as described in claim 7 wherein 2,2- (p-phenylenedioxy) diethanol is condensed with di-nbutyl carbonate in the presence of magnesium titanium butoxide.

9. A process as defined in claim 7 wherein 2,2- sulfonyl bis(p-phenyleneoxy)) diethanol is condensed with di-n-butyl carbonate in the presence of magnesium titanium butoxide.

10. A process as defined in claim 7 wherein 2,2'-(oxobis(p-phenyleneoxy))diethanol is condensed with di-nbutyl carbonate in the presence of magnesium titanium butoxide.

11. A process as defined in claim 7 wherein 2,2'-(isopropylidene bis(p-phenyleneoxy)) diethanol is condensed with di-n-butyl carbonate in the presence of magnesium titanium butoxide.

12. A process as defined in claim 7 wherein 2,2'-(l,5- naphthalenedioxy) diethanol is condensed with di-nbutyl carbonate in the presence of magnesium titanium butoxide.

13. A film prepared from a polycarbonate defined by claim 1.

14. A fiber prepared from a polycarbonate defined by claim 1.

No references cited. 

1. A HIGHLY POLYMERIC LINEAR POLYCARBONATE CONTAINING RECURING GROUPS HAVING THE FOLLOWING GENERAL FORMULA: 